Use of .getPropertyCSSValue()

How to get the exact value of css style in testcomplete ?

please check below image 

i want to get border-width as thin

border-style as solid

border color as rgba(0,0,0,0.87)

border radius as 0px

i am using .getPropertCSSValue() please check below code:

var ObjectStyle = NameMapping.Sys.browser.pagePlus1Connect3.panelRoot.panel.panel.panel.panel.panel.panel.panel.panel.panel;
Log.Message(ObjectStyle.style.getPropertyCSSValue("border-width"));

getting error-